1 - ticket life - the difference from open time to close time for the ticket as the close time is based on the IM process as when the ticket is resolved / closed
2 - service resolution time - this can be from the monitoring tool or from when the customer said the app was down to when the support team said it was up or when the customer said it was up
3 - service up/down time - monitoring tool or system log from machine providing the service

It all just depends on which values are better, best or part of the SLA / OLA parameters

Lets say at 9:00 AM users have reported that Application A is unavailable . At 10:00 AM support team has confirmed that the issue has been resolved.However usres have only confirmed at 12:00 noon.

My question is , what shall we consider as an outage duration.

a) 1 hr.

b)2 hrs

3 hours according to my arithmetic. It is not back again until a user can use it. So if, for a couple of hours, you forget to tell the users it is fixed, then it is still out until you do and they verify it.

But I would not make the calculation on the basis of reports. I would look at the logs and see when it stopped logging for the start time and I would look at the time of the next successful login as the time it became available again. It is a good thing to keep availability separate from incident management.

As John said, it depends on what the figure is for. For example it could have crashed at 05.00, but it is not required until 09.00. From a service availability point of view the time before 9 may not count, but it might be useful to know that it can be down for four hours without any monitoring (manual or automatic) picking it up._________________"Method goes far to prevent trouble in business: for it makes the task easy, hinders confusion, saves abundance of time, and instructs those that have business depending, both what to do and what to hope."
William Penn 1644-1718

[Thanks a lot for clarifying the doubt . You are right , if the outage duration falls outside the agreed service hours , shall not be added to the outage duration.]

I guess UNViking BRIEFly didn't said that if outage duration falls outside the agreed service hours, it shall not be considered as outage. All he mentioned is IT DEPENDS on what you want to show. Do you want to show it to have your customer use it against you? I guess no. Then try some LDLAS. Show them that though there was an outage, the components A, B, C, D constituting the service were available 99.95% of times. LDLAS best works when the data is broken down in bite chunks. Say that 6/7th of the application was usable when the customer cried outage. So, when there was an outage, the service was 85% available. Show them that at this rate the customer can expect a response rate between 85% to 99.995%. IT Depends how good its sold._________________regards,

Vivek
"the only statistics you can trust are those you falsified yourself"
Winston Churchill

What I have said below is from the perspective of Service availability.
[Thanks a lot for clarifying the doubt . You are right , if the outage duration falls outside the agreed service hours , shall not be added to the outage duration.]

If the agreed business hours is 9:00 AM to 5:00 PM in a day and the service was unavailable from 6:00 PM and became available before their login time . As per my understanding the outage duration is 00:00:00.

Please note Incident management process has to perfrom its job irrespective of the outage happening within agreed service hours or not.